Overview

This project is developed to enable velocity control using Radio Controller (RC) in offboard mode while using the ARPL Autonomy stack. The ROS-RC-Wrapper is a ROS Package that maps the RCin topics from Mavros to Body Velocity commands in the ARPL Quadrotor control.

Subscribers and Services

This package mainly subscribes to Mavros and calls multiple services from the Mav_manager package. The following is a list Subscribers and Services used by the package.

Object Type	Topic Name	Description
Subscriber	/mavros/rc/in	Stick input from the RC streamed via Mavros
Subscriber	/mavros/param/get	PX4 parameters set in the PX4 firmware
Service	/mav_services/setDesVelInBodyFrame	Desired Velocity goals in Body frame
Service	/mav_services/land	Land service
Service	/mav_services/hover	Hover service
Service	/mav_services/motors	Motors-on Service
Service	/mav_services/takeoff	Takeoff Service

Installation

The installation of the package is straight forward. Make sure to source setup.bash before begining installation of the package.

cd ~/path/to/your/workspace/src
git clone https://github.com/arplaboratory/ROS-RC-Wrapper.git
catkin build rc_control
source ~/path/to/your/workspace/devel/setup.bash 

Running

You can run the package using rosrun in the following way

rosrun rc_control rc_command

Usage

To send body velocity goals using the RC follow these steps,

Set up

1. Once the ARPL Autonomy Stack is running you can start the ROS-RC-Wrapper package using rosrun
2. Follow the regular procedure until motors-on in the RVIZ interface.

Takeoff

1. After motors-on is clicked, toggle SWITCH F on the RC to POS 1 to switch to "Offboard" mode.
2. Toggle SWITCH D to POS 1 to takeoff.

Note

At this point the robot will be flying and will be in offboard mode as usual.

Velocity Control

1. Toggle SWITCH F to POS 0 to enable velocity control.

Important

Make sure both the sticks are centered before toggling to Velocity mode to avoid publishing any unnecesary goals during transition.

Landing

1. Toggle the SWITCH F back to POS 1 to disable Velocity control.
2. Toggle SWITCH D to POS 0 to land the robot.

Disarming

1. To disarm the Robot, switch mode back to stabilize by toggling SWITCH F to POS 2
2. Then disarm by toggling the disarm switch SWITCH A to POS 1

Warning

Make sure the THROTTLE STICK is set to ZERO before switching mode to stabilize. This is to avoid commanding high throttle during disarming.

Image for reference